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1NHSBT Feb 21 – Convalescent Plasma Programme
Convalescent Plasma for the
treatment of COVID-19:
not the results
Dr Lise Estcourt
Director Clinical Trials Units, NHSBT
2NHSBT Feb 21 – Convalescent Plasma Programme
▪ What is convalescent plasma
▪ What is the evidence from previous infectious diseases
▪ What is the current evidence
▪ What next
Summary of talk
What is convalescent plasma?
Luke et al. Ann Intern Med. 2006;145:599-609.
Mair-Jenkins et al. The Journal of Infectious Diseases 2015;211:80–90.
SARS
Influenza
Influenza
Influenza
Influenza
2011
1919
1919
2004
1919
Non-randomised study – 84 participants compared to 418 historical control
2x 200 to 250mls convalescent plasma
Risk of death 31% CCP vs. 38% control group (risk difference, −7%; 95% CI, −18 to 4)(adjusted for age and CT value −3 %; 95% CI, −13 to 8)
Antibody levels not assessed prior to transfusion
Why were major convalescent plasma programmes not part of pandemic planning?
▪ Evidence not based on high quality evidence
▪ Observed lower mortality could reflect selection bias or publication bias
▪ Questions of potential harm remained open - antibody dependent enhancement
▪ Without good evidence for effectiveness and safety, health services did not prioritise investment in co-ordinated collection, testing, manufacture and issue of CP
Convalescent plasma in COVID-19
100 ongoing convalescent plasma RCTs around the world
15 RCTs around the world recruiting 500 or more participants
Study Country Number of participants
Severity of illness
Days from symptom onset
Intervention Control
Agarwal India 464 WHO 5 8 CP Standard care
Siminovich Argentina 333 WHO 4 to 5 8 CP Saline
Libster Argentina 160 WHO 2 to 3 <3 CP Saline
Li China 103 WHO ≥ 5 27 to 30 CP Standard care
Rasheed Iraq 49 WHO ≥ 6 21 to 28 CP Standard care
Hamdy-Salman Egypt 30 WHO ≥ 5 30 CP Saline
Gharbaran Netherlands 86 WHO ≥ 4 9 to 11 CP Standard care
Avendano Sola Spain 81 WHO 4 to 5 8 CP Standard care
Ray India 80 WHO 5 to 6 NR CP Standard care
Balcells Chile 58 WHO 4 to 6 5 to 6 CP Delayed CP
Al-Qhatani Bahrain 40 WHO 5 to 7 NR CP Standard care
Bajpai India 29 WHO 5 to 7 NR CP Plasma
Outpatients
Primary outcome: severe respiratory disease defined as a respiratory rate ≥30 and/or an O2sat<93% in room air up to 25 days
Stopped early - decreased numbers of cases
16% (13/80) receiving plasma vs. 31% receiving placebo developed severe respiratory disease [RR(95%CI)= 0.52(0.29,0.94); p=0.026)] RRR=48%
2 receiving plasma vs. 4 receiving placebo died (NS).
160 participants hospitalised with COVID-19ArgentinaMulticentre - blindedElderly outpatients within 72 hours symptom onset (≥ 75 yrs or 65 to 74 with comorbidities)CP given as 250mlsAb titre >1:1000 IgG S
Inpatients
Primary outcome: composite of progression to severe disease (PaO2/FiO2 ratio <100mm Hg) any time within 28 days of enrolment or all cause mortality at 28 days
Trial comparing convalescent plasma versus standard care
No difference seen in primary or secondary outcomes
Underpowered
Levels of antibody in CCP very low or undetectable
Participants hospitalised with moderate COVID-19IndiaMulticentre – open label464 adultsAdults (Median age 52)PaO2/FiO2 ratio 200 to 300mm Hg or RR > 24 or O2 ≤ 93%Excluded: patients with PaO2/FiO2 <200 mm Hg or shock
CP given as two 200ml units 24 hours apartMedian Ab titre not measured prospectivelyOnly 70% of participants received at least 1 unit of CCP with detectable neutralising Abs (1:20)
Only 28% of participants received at least 1 unit of CCP with neutralising Abs ≥ 1:80.
Primary outcome: clinical status 30 days after intervention1- death2- invasive ventilatory support 3- hospitalized with supplemental oxygen requirements 4- hospitalized without supplemental oxygen requirements 5- discharged without full return of baseline physical function 6- discharged with full return of baseline physical function
Trial comparing convalescent plasma versus placebo
Overall mortality was 10.96% in the convalescent plasma group and 11.43% in the placebo group, for a risk difference of −0.46 percentage points (95% CI, −7.8 to 6.8)
Only 80% power to detect proportional OR 1.8
Participants hospitalised with severe COVID-19ArgentinaMulticentre – blinded333 adults (228 CP:105 placebo)Adults (Median age 62)PaO2/FiO2 ratio < 300mm Hg or O2 < 93% or SOFA score ≥ 2 points above baselineExcluded: MV or organ failure
CP given as single donor or plasma pool (median 500mls)Ab titre > 1:1000 Ig G (median 1:3200)
Median neutralising antibody titre 1:300, IQR 136-511
Trial comparing convalescent plasma versus standard care
Suggested decreased mortality 1/21 versus 8/28
Suggested decreased duration of severe disease by 4 days
Underpowered
Duration of infection prior to enrolment 14 to 16 days
Participants hospitalised with life-threatening COVID-19IraqMulticentre49 adults
CP given as one 400ml transfusion over 2 hours
Median Ab titre not measured prospectivelyDonors were moderately or strongly positive on SARS-CoV-2 ELISA
Convalescent plasma UK trial• Hospitalised patients – children and adults
• CP versus standard care (+/- other randomised treatments)
• 2 units of CP given on study days 1 & 2
• Powered to see 20% reduction in overall 28-day mortality
20NHSBT Feb 21 – Convalescent Plasma Programme
Anticipated trials progress
Epidemic curve: closest to SAGE RWC
Trial Completion: Anticipated and Actual
w/c
21NHSBT Feb 21 – Convalescent Plasma Programme
Close of RECOVERY trial
• Enhanced power to look at anti-SARS-CoV antibody negative group
• Study closed to recruitment for mechanically ventilated on Jan 7th
• Study closed on Jan 15th
• total approx. 12000 recruited
• Preliminary analysis
• 1873 reported deaths among 10,406 randomised patients
• no significant difference in the primary endpoint of 28-day mortality
• 18% CP vs. 18% usual care alone; risk ratio 1.04 [95%CI 0.95-1.14]; p=0.34
• No signal for harm
22NHSBT Feb 21 – Convalescent Plasma Programme
Patient characteristic in RECOVERY trial
• DMC had results of anti-SARS-CoV antibody test for their analyses
• 40% of patients were antibody negative
• Patient characteristics
• Median time since symptom onset was 9 days
• 6% of patients not requiring oxygen
• 86% of patients on supplementary oxygen
• 8% of patients mechanically ventilated
• Spectrum of disease is moderate to severe
• a small minority (n=600) not requiring oxygen at time of enrolment
23NHSBT Feb 21 – Convalescent Plasma Programme
Analysis of RECOVERY trial
• All cause 28 day mortality
• Time to discharge if alive
• Use of mechanical ventilation
• Pre-specified sub-group analysis (approx. terciles)
• Age, sex, ethnicity
• Pre-existing antibody
• No oxygen or oxygen or ventilation
• <7 and >7 days since onset of symptoms
• Additional non-randomised comparison of antibody levels in donor plasma
• EUROIMMUNE, Roche anti-S ELISA and Live virus nAbs (Deb Hung, BROAD)
24NHSBT Feb 21 – Convalescent Plasma Programme
Antibody titres of initial sample of donors
• In first 400 donors EUROIMMUNE S/CO > 6
• Mean nAb 1:399 with median nAb ~ 1:250 but may have changed during trial
• In the trials
• 25% received two units with EUROIMMUNE 6-7.99
• 50% received one units with EUROIMMUNE 6-7.99 and one unit 8-12
• 25% received two units with EUROIMMUNE 8-12
• Measurement of individual unit nAbs will allow antibody dose to be determined
• Mutation mismatch between donor and recipient cannot be determined
• Effective titre may be reduced to variable extent ~ three fold
Convalescent plasma UK trial
• Adults admitted to ITU within last 48 hours
• Confirmed COVID
• CP versus standard care (+/- other randomised treatments)
• CP on study day 1 and day 2
• Intensive blood and respiratory sampling for a subgroup (approx. 200 participants)
26NHSBT Feb 21 – Convalescent Plasma Programme
Close of REMAP-CAP trial
• Recruitment to severe patients closed on Jan 11th by DSMC
• 2000 recruited
• For severe patients
• 921 patients with 28 day-follow up
• Low probability of < 2.2% that CP decreased the number of days requiring intensive
care support or death by 20% or more
• Recruitment for moderate patients closed on Jan 18th after RECOVERY closed
27NHSBT Feb 21 – Convalescent Plasma Programme
Analysis for REMAP-CAP trial
• Organ support free days
• 28 day mortality
• Progression to mechanical ventilation or ECMO
• Time to discharge from ICU and from hospital
• SAEs
• Models for sub-group analysis of organ support free days
• Age, sex, site, time during pandemic, convalescent plasma and control
interventions, corticosteroid and immune modulation interventions
• Baseline clinical status – mechanical ventilation
• Presence of virus by RT-PCR at enrolment
• Presence of anti-SARSCoV-2-antibodies at enrolment (28% antibody neg)
• Antibody levels in donor plasma
• EUROIMMUNE, Roche anti-S ELISA and live virus nAbs
• Individual patient analysis will combine data from both trial
28NHSBT Feb 21 – Convalescent Plasma Programme
Antibody based therapy for COVID-19
• Evidence of substantial effect of convalescent plasma in Argentinian RCT with
160 patients (Libster et al NEJM 2021 )
• vulnerable patients (> 75 or 65-74 with co-morbidities) only 3d of symptoms
• given one unit of high-titre plasma (28% of donors accepted)
• respiratory disease in 13/80 (16%) with CP and 25/80 (30%) in controls
• RR 0.52 (85% CI 0.29-0.94)
• Substantial dose effect
• Higher than median dose RR 0.29
• Lower than median dose RR 0.75
• US data observational study of CP (Joyner et al NEJM 2021)
• 30-day mortality in 115/515 (22.3%) in those receiving one unit of high titre,
549/2002 (27.2%) of medium titre 166/561 (29.6%) low titre CP
• Mortality in high vs low titre RR 0.62 not ventilated, RR1.02 ventilated
29NHSBT Feb 21 – Convalescent Plasma Programme
Antibody based therapy for COVID-19
• Preliminary results from two large randomised trials do not show overall benefit
for moderately or severely ill patients
• No evidence for effects in mechanically ventilated patients
• Analyses of sub-groups may show an effect and one may speculate that effects
are now only likely to be seen in those
• Treated early within 7 days of symptoms appearing
• and/or treated with higher viral nAb titres
• Final results early March
30NHSBT Feb 21 – Convalescent Plasma Programme
A third CP trial: COVIC-19
• Planning for a third trial for pre-hospital immunocompromised and vulnerable
patients testing positive for COVID-19
• Over 70s
• Or adults
• Chemotherapy
• Haem-onc patients, HSCT and solid organ transplant patients
• Other immunosuppressive therapy or conditions
• Intervention – high titre convalescent plasma as out-patient or in the community
• Outcome – hospital admission with moderate or severe COVID-19
• Significant need and significant numbers may remain after vaccination
• International recruitment
31NHSBT Feb 21 – Convalescent Plasma Programme
Summary and next steps
• Still no solid RCT evidence to drive policy
– No efficacy seen in REMAP CAP and RECOVERY and final analysis now underway
– Significant sub-groups of early disease and high-titre remain to be analysed
• Planning for a third trial for pre-hospital immunocompromised or vulnerable patients
testing positive for COVID-19
• Challenges of escape variants and treatment of severely immunocompromised
patients
• Continued need for collection of high-titre plasma
– To support trials
– To provide plasma if the planned trial or other trials change policy
– Hospitalised, male and older COVID patients more likely to have high antibody tite
• Development of hyperimmune immunoglobulin
32NHSBT Feb 21 – Convalescent Plasma Programme
Acknowledgements
CP
ProgrammeBo
ard
CP Programme
Leadership
Steering
Group
NHSBT & Devolved UK Blood
ServicesMillie Banerjee and Board
Betsy Bassis and Exec Team
Programme LeadershipGail Miflin
Gerry Gogarty
David Roberts
Tony Staincliffe
Donor OutreachDarren Bowen
Steven Dixon-Mould
CollectionDonna Cullen
Andrew Gibb
ManufacturingDebbie Richards
TestingJo Sells
DigitalMarian Zelman
Patients & NHSBT CTUSheila MacLennan
Emily Arbon
Alison Deary
Amy Evans
Chloe Fitzpatrick-Creamer
Claire Foley
Cara Hudson
Emma Laing
Ana Mora
Gillian Powter
Samaher Sweity
NHSBT R&D Rutger Ploeg
Marta Olivera
Sarah Cross
Pat Tsang
Ullrich Leuschner
Abigail Laikanra
Nic Ciccone
OxfordDerrick Crook
Gavin Screaton
Phillipa Matthews
Alain Townsend
Julie Xiao
PHEHeli Harvala
Maria Zambon
Samreen Ijaz
Tim Brooks
Ines Ushiro-Lumb
QAFidelma Murphy
Peter Senior
Jeremy Kellington
CommsStephen Bailey
Stephen Park
Bruce Willan
Mike Murphy
REMAP CAPDavid Menon
Manu Shankar Hari
Tony Gordon
Steve Webb
RECOVERYPeter Horby
Richard Hayes
Martin Landray
Leon Peto
NIHR
EU Commission
33NHSBT Nov 2020 – Convalescent Plasma Programme
Acknowledgements
CP
ProgrammeBo
ard
CP Programme
Leadership
Steering
Group
https://www.nhsbt.nhs.uk/how-you-can-help/convalescent-plasma-clinical-trial/
Especially welcome if hospitalised OR men OR >35 yo
Very interested in taking NHS staff with good level of anti-COVID antibodies
Call 0300 123 23 23 and mention you are NHS colleagues